Step 1:
This is the front of the paper, the backside is completely yellow.
Prefold in half over these 4 lines.

Step 6:
First, valley-fold over the 2 lines at the bottom right. Then, mountain-fold over the 2 lines next to them. Continue making valley- and mountain-folds until the 2 lines on the top left.
All lines are already prefolded.

Step 5:
Prefold over these 4 lines.

Step 2:
Mountain-fold over these 4 lines.
Then, turn the model.

Step 4:
Turn the model.

Step 3:
Valley-fold over these lines.

Step 10:
Here a part of the folds from step 9 is already done.

Step 8:
Unfold and open the model

Step 9:
Sink-fold over the prefolded lines.

Step 7:
Prefold over this line.

Step 16:
And here all petals are folded downwards. The flower is ready...

Step 15:
Here a few more petals are folded downwards.

Step 12:
Turn the model

Step 11:
Press the model a little further inwards, see pink arrows

Step 14:
This is the petal which is folded downwards. Repeat step 13 on the other seven petals.

Step 13:
Fold the petal indicated by the arrow downwards. Do this by making a valley-fold over the left line and a mountain-fold over the line on the right.
The left line is already prefolded.

Step 21:
Press the tip of the leaf flat between your fingers.

Make two large and one smaller leaf. Glue the leafs to the backside of the flower.

If you prefer using a stem,
You can find instructions for paper stems here

Step 19:
Valley-fold over these lines.

Step 20:
Turn the model.

Step 18:
Valley-fold over these two lines.

Step 17:
The leaf paper is green on both sides.
Valley-fold over this line.